A Bonded Double-Doped Graphene Nanoribbon Framework for Advanced Electrocatalysis

Abstract

The preparation of a low-cost, high-efficient, and stable electrocatalyst as an alternative to platinum for the oxygen reduction reaction (ORR) is especially important to various energy storage components, such as fuel cells and metal-air batteries. Here, we report a new type of bonded double-doped graphene nanoribbon-based nonprecious metal catalysts in which Fe3C nanoparticles embedded in Fe-N-doped graphene nanoribbon (GNRs) frameworks through a simple pyrolysis. The as-obtained catalyst possesses several desirable merits for the ORR, such as diverse high-efficiency catalytic sites, a high specific surface area, an ideal hierarchical cellular structure, and a highly conductive N-doped GNR network. Accordingly, the prepared catalyst shows a superior ORR activity (an onset potential of 0.02 V and a half-wave potential of -0.148 V versus an Ag/AgCl electrode) in alkaline media, close to the commercial Pt/C catalyst. Moreover, it also displays good ORR behavior in an acidic solution.

Highly efficient electrocatalysts derived from carbon black supported non-precious metal macrocycle catalysts for oxygen reduction reaction

“…With outstanding oxygen reduction reaction (ORR) activity, Pt and alloys catalysts are regarded as the most effective catalysts. Unfortunately, the scarcity and high cost have greatly limited the commercialization of fuel cells [5][6][7][8] . There is no denying that Ptbased catalysts contribute nearly half of the total cost of the fuel cell stacks [6,9] .…”

High Power Output Microbial Fuel Cell using Nitrogen and Iron Co‐Doped Carbon Nanospheres as Oxygen‐Reduction Catalyst

“…The TEM image (Figure b) showed that several black dots with a size of 20–70 nm were embedded in the pristine amorphous carbon after doping with N and trace Fe, which was assigned to the heavy atoms, that is, the Fe moieties in this case . These Fe moieties were confirmed as Fe 3 C, which played a key role for the high activity of the Fe‐doped catalyst. The HRTEM test results revealed that each Fe 3 C nanoparticle was encapsulated by a graphitic carbon shell (with a thickness of 10–20 nm) to form a core–shell structure, as shown in Figure c. An interplanar spacing of 0.401 nm was identified (the top‐right inset of Figure c), which can be assigned to the (110) lattice planes of the Fe 3 C nanoparticles.…”

“…The peak located at approximately 26.5° was indexed to the (002) plane of the graphitic carbon (JCPDS No. 41‐1487), which is consistent with the TEM results. The peaks of Fe 3 C were much stronger than those reported in previous studies, which was probably the key reason for the high activity of NFe/CNS.…”

“…41‐1487), which is consistent with the TEM results. The peaks of Fe 3 C were much stronger than those reported in previous studies, which was probably the key reason for the high activity of NFe/CNS. A high‐resolution XPS scan was conducted to gain further insight into the composition and chemical state of the elements.…”

“…Although the peaks in the HRTEM spectra of Fe 2p were too weak to further identify the exact chemical state of Fe (Figure S6), the high‐resolution N 1s spectra of NFe/CNS (Figure b) indicated the existence of Fe–N species (399.7 eV) including pyridinic N (398.2 eV), pyrrolic N (400.7 eV), and graphitic N (401.9 eV) . These microscopic characterizations results showed that the functional groups that play critical roles in the high activity of the catalysts, such as Fe 3 C, Fe–N, and pyridinic N, had been successfully synthesized in NFe/CNS.…”